# OCEANOGRAPHY AND WEATHER

## What is oceanography?

Oceanography is the study of the world's oceans, including the waters and everything in them: animals, plants, and minerals. Oceanographers study the physics, chemistry, biology, and geology of the seas. Oceanography is important to understand in relation to meteorology for many reasons. For example, the oceans have a lot to do with heat absorption, distribution, and reflection, as well as with the water cycle and with levels of carbon dioxide in the atmosphere, among other influences.

## How much water is there on Earth?

Including all the world's oceans, lakes, rivers, as well as all the water contained in the Earth's soils, in the atmosphere, and in icebergs and other frozen forms,

This map of the Ring of Fire indicates the Mid Ocean Ridge Systems with a dotted line, and the Island Arc/Trench Systems with a solid yellow line. (Pacific Ring of Fire 2004 Expedition. NOAA Office of Ocean Exploration; Dr. Bob Embley, NOAA PMEL, Chief Scientist)

scientists estimate that there is 3.7 x 1014 gallons (1.4 x 1015 liters) of water on the planet.

## How much water is in the world's oceans?

Earth is about 70 percent covered by oceans and seas, and about 97 percent of the world's total water is contained in the oceans. Two percent of this water is in the form of ice.

## What is a hydrometer?

A hydrometer measures the specific gravity of a liquid. It is used to determine the density of a fluid compared to the density of pure water at 60°F (15.5°C). This can be handy when seeking a reading for the salinity of water, such as when taking samples of sea water.

## How much water evaporates from the world's oceans?

Incredibly, over 1.32 x 1017 gallons (500,000 cubic kilometers) of water evaporate from the oceans each year. Fortunately, that water is replenished by 1.19 x 1017 gallons (450,000 cubic kilometers) of rain and snowfall, as well as waters draining into the oceans and seas from rivers and streams.

## How much drinkable freshwater is there on Earth?

Only 2.59 percent of all the water on our planet is freshwater. However, much of that water is now polluted, and hydrologists and environmentalists estimate that only about one percent of the planet's total water supply is clean enough to drink.

## What is Arctic sea smoke?

When extremely cold air blows over Arctic ice packs, the warmer seawater beneath causes fog to form when it comes into contact with the colder air. As the fog rises, it may appear to be smoke plumes.

## What are growlers?

Growlers are pieces of floating ice that have broken off from an iceberg.

### Which freezes more quickly— cold or hot water?

An old wives' tale that still circulates in American homes is that, if you wish to freeze ice quickly in an ice tray, put hot tap water in it and then put it in the freezer. Of course, many homes have automatic ice dispensers in their refrigerators, so this tale is beginning to die out somewhat. Let's dispel the myth now, however, and say that, no, hot water will not freeze faster than cold. However, what does work is boiling the water, then allowing it to cool down to a tepid temperature. Boiling the water removes air bubbles in the water, increasing thermal conductivity, and allow-

What unusual floating objects have been used to help chart currents in the oceans?

In a rather humorous example of kismet, oceanographers have been taking advantage of a 1990 accident in which a Korean cargo ship accidentally dumped 80,000 Nike shoes into the ocean. Since then, whenever these shoes have been found floating in the Pacific Ocean and elsewhere, oceanographers have taken note, tracking where the accident originally occurred and comparing it with the location where the shoes were found. In this way, they were able to gather additional information about currents.

It wasn't long before another accident created a new opportunity for studying the currents. In January 1992 a ship hauling toys lost part of its cargo in a storm. Nearly 30,000 rubber ducks, frogs, turtles, and beavers fell into the ocean. As with the athletic shoes, these toys, as they washed up on various shorelines, served as excellent indicators of the course taken by ocean currents.

ing the water to freeze more quickly. Of course, the time wasted boiling the water and then allowing it to cool would have been better spent by simply putting lukewarm water in the freezer in the first place! Not to mention that it would be more energy efficient not to boil the water.

## Do oceans get more rain than land?

The oceans receive just over their share, percentage-wise, of the world's precipitation, about 70 percent. The remaining 30 percent of precipitation falls on the continents. Some areas of the world receive far more precipitation than others. Some parts of equatorial South America, Africa, Southeast Asia, and nearby islands receive over 200 inches (500 centimeters) of rain a year, while some desert areas receive only a fraction of an inch of rain per year.

## What is lake effect snow?

Water evaporating off lakes can increase air humidity and encourage cloud formation and precipitation in areas near shorelines. As cold air moves over a water body such as a lake, it picks up moisture; then, when the clouds reach the shoreline, the air moves upwards in what is called the orographic effect. This, in turn, creates concentrated bands of precipitation that then release precipitation within relatively short distances of shorelines.

Some record snowfalls have been documented as a result of the lake effect. For example, on January 17, 1959, 51 inches (129.5 centimeters) of snow fell on Bennetts Bridge, New York, over a 16-hour period. Buffalo, New York, is infamous for being buried in snow because of its proximity to Lake Erie. The winter of 1976 to 1977, for instance, saw the city experience 30-foot snow drifts. Storms with 70mile- (113-kilometer)-per-hour winds and bitter temperatures led to the deaths of 29 people that season.

## What is the thermocline?

Imagine the water in a sea or ocean as being similar to very dense air in the atmosphere. Just like with the air, layers of water can have different temperatures and pressures, with warm waters generally being on top of colder layers of water. The difference between the temperatures in these layers is called the thermocline.

## At what temperature does sea water freeze?

While the amount of salt and other minerals and impurities in sea water makes a difference, in general sea water freezes at about 28°F (-2.2°C).